Dengue type 1 epidemic with haemorrhagic manifestations in Fiji, 1989-90

A dengue type 1 epidemic occurred in Fiji between July 1989 and July 1990. Virus isolation in C6/36 cell cultures and Toxorhynchites mosquitos yielded 36 strains. Of the 3686 cases recorded by the Ministry of Health, 60% involved indigenous Fijians and 37%, Indians. A house-to-house survey revealed that a large majority of patients had classical dengue symptoms and 8% reported haemorrhagic manifestations. Among the children and adults hospitalized for dengue, 43% had haemorrhagic manifestations, including epistaxis, gingival bleeding, haematemesis, melaena and haematuria. A total of 15 patients with haemorrhagic manifestations and/or shock died, 10 of whom were aged 0-15 years; the diagnoses were confirmed in four cases by virus isolation or serology.Researchers reviewed the medical records of all cases of dengue and dengue-like illness in Fiji since 1971. During March-April 1990, in Fiji, interviews were conducted with 426 occupants of 81 randomly selected houses in Suva and its surrounding areas to examine the relationship between the incidence of true dengue and dengue-like illnesses and the reported incidence. 60% of the persons interviewed were Fijians and 31% were Indians. Health workers collected blood samples from acute cases. 36 strains of dengue 1 virus was isolated. A fever lasting more than 3 days accompanied by at least one of the following symptoms denoted dengue or dengue-like illness: headache, joint pains, muscle pains, rash, epigastric discomfort, and bleeding. There was an outbreak of clinical dengue 1 during 1989-1990 involving 3686 cases. The 1975 outbreak involved 1600-2400 cases of dengue hemorrhagic fever. The 1989-1990 incidence was higher among Fijians than Indians (60% vs. 37%). The dengue epidemic peaked in November 1989 (about 900 cases). The rate of dengue hemorrhagic fever was 8% (15 cases). Hemorrhage manifestations included nosebleeds (8 persons), gingival bleeding (2), vomiting of blood (2), blood in the urine (3), and passage of dark stools stained with blood (3). The case fatality rate was 8%. Hemorrhages of the stomach and lungs occurred in most fatal cases. 10 of the 15 fatal cases were aged 10-15 years. 182 (43%) of the respondents in the household survey had reported dengue-like illness in the last 6 months. Children were more likely to have had dengue than adults (51% of 0-9 year olds and 61% of 10-19 year olds vs. 32-33% for all other age groups). Among hospitalized dengue cases, 43% experienced hemorrhages.